docabuzar wrote:
If Father's age is 1 less than twice the son's age, what is the son's age?
A. The digits MN making up the father's age are reversed in the son's age i.e NM.
B. Father is at least 25 years older than son
I m not sure of the answer but i think its "A"
Gimme Kudos if you like the question
Look at the big picture. You can solve this question quickly using intuition.
Father's age is almost as much as twice of son's age. (just 1 less)
Son's age = NM, Father's age = MN
Say, son's age is 12 then father's is 21 (3 less than twice)
Say, son's age is 13 then father's is 31 (much more than twice)
I hope you understand that you can give up on the 10s series here because the gap will keep widening (diff b/w 14 and 41 will be even more)
Say, son's age is 24 then father's is 42 (much less than twice)
Say, son's age is 25, then father's is 52 (more than twice so give up on the 20s series too)
Say son's age is 36, then father's is 63 (much less than twice)
Say son's age is 37, then father's is 73 (1 less than twice. Got it!)
It's easy to say that there will be no other such combination because 49, 94 doesn't work. Nothing in 50s, 60s and so on will work because we need to stick to 2 digit numbers.
Hence, only statement 1 is sufficient.
_________________
Karishma
Veritas Prep GMAT Instructor
Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >